On This Day . . .

Light Amplification by Stimulated Emission of Radiation

May 16, First Laser Created

On this day in 1960, Theodore H. Maiman operated the first functioning laser, at Hughes Research Laboratories, Malibu, California. Maiman was not the first to apply for patents but he was the first to create an operating laser device.

Maiman with his first laser light

Maiman used a solid-state flash lamp-pumped synthetic ruby crystal to produce red laser light, at 694 nanometers wavelength. The light produced by this device was not a true beam as we think of most lasers today, but rather a pulse.

Maiman’s disassembled laser

A laser emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term “laser” originated as an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers differ from other sources of light because they emit light coherently.

What does that mean? Well its spatial coherence simply means that a laser can be focused to a tight spot, and this enables applications like laser cutting and laser lithography. Its spatial coherence also keeps a laser beam collimated (to make parallel or bring into a line) over long distances, and this enables laser pointers to work. Lasers also have high temporal coherence which allows them to have a very narrow spectrum, i.e., they only emit a single color of light. Their temporal coherence also allows them to emit pulses of light that only last a femtosecond (one quadrillionth of a second). That’s fast!!!

Lasers are used in many common consumer devices like DVD players, laser printers, and barcode scanners. They are used for laser surgery, various skin treatments, and in industry for cutting and welding materials. They are used in military and law enforcement devices for marking targets and measuring range and speed. You’ve seen lasers in lighting displays at entertainment venues. Lasers also have many important applications in scientific research.

Wonderful tribute from Ted’s wife Kathleen: How the First Laser was Made